Abstract: A d-c converter for inclusion in a miniature electronic device, such as an electronic wristwatch having a d-c supply source, the converter functioning to increase or decrease the voltage of this source. The converter includes a transformer whose primary is connected to the source through a periodically-actuated chopper to produce an alternating voltage, the secondary of the transformer being connected to a rectifier circuit having at least one controllable switch element whose on-off state is governed in synchronism with the chopper whereby the switch element acts to rectify the secondary voltage.

Abstract: A miniature electronic timepiece whose analog-display time-indicating hands are driven by the rotor of a stepping motor actuated by low-frequency periodic timing pulses derived by frequency division from a high-frequency crystal-controlled time base. This motor, in addition to a stator coil wound on a core, includes an auxiliary coil wound on the same core to define a transformer whose primary is the auxiliary coil and whose secondary is the stator coil. To power the electronic watch, a voltage at a predetermined level is required, this being supplied by a converter formed by an electronic chopper interposed between the primary of the transformer and a d-c source whose output is at a different voltage level. The d-c voltage applied to the primary is periodically interrupted, the resultant a-c voltage yielded by the secondary being rectified to provide the desired power voltage.

Abstract: A miniature electronic timepiece whose analog-display time-indicating hands are driven by the rotor of a stepping motor actuated by low-frequency periodic timing pulses derived by frequency division from a high-frequency crystal-controlled time base. The motor, in addition to a stator coil wound on a core, includes an auxiliary coil wound on the same core to define a transformer whose primary is the auxiliary coil and whose secondary is the stator coil. To power the electronic watch, a voltage at a predetermined level is required, this being supplied by a converter formed by an electronic chopper interposed between the primary of the transformer and a d-c source whose output is at a different voltage level. Thus the d-c voltage applied to the primary is periodically interrupted, the resultant a-c voltage yielded by the secondary being rectified to provide the desired power voltage.

Abstract: An electronic watch wherein pulses from a high-frequency standard are converted by a frequency divider into low-frequency timing pulses which are supplied to a stepping motor to advance the hands of the time display. In order to automatically effect a rapid correction of the seconds hand display when it deviates from precise time, a system is provided that includes an actuating element accessible to the user of the watch and operatively coupled to a switch connected through a reset line to several of the last stages of the frequency divider to effect a reset thereof upon activation of the switch. Also reset when the switch is activated is a reference counter supplied with pulses by the frequency divider. The divider feeds pulses by way of a logic circuit to the stepping motor and to a synchronous counter which is maintained in synchronism with the time display.